Longman Dictionary of Contemporary English - hysteria

~ n 1 extreme excitement that makes people cry, laugh, shout etc uncontrollably  (an outbreak of hysteria among the group's fans) 2 a situation in which a lot of people are affected by the same extreme emotion such as fear or anger which often makes them behave in an unreasonable way  (anti-communist hysteria | mass hysteria)  (Since the General's death, the population has been gripped by mass hysteria.) 3 technical a medical condition which upsets someone's emotions and makes them suddenly feel very nervous, excited, anxious etc - hysteric adj